Pneumatically operated circuit interrupter



Aug. l0, 1954 J. B. MacNE|LL Filed Feb. 23. 1951 PNEUMATICALLY OPERATED CIRCUIT INTERRUPTER 2 Sheets-Sheet 1 Aug. 10, 1954 J. B. McNl-:ILL 2,686,237

PNEUMATICALLY OPERATED CIRCUIT INTERRUPTER Fied Feb. 23, 1951 2 sheets-sheet 2 Mfg@ W.

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John B. MocNeill.

Patented Aug. 10, 1954 PNEUMATICALLY OPERATED CIRCUIT INTERRUPTER John B. MacNeill, Wilkinsburg,

Pa., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 23, 1951, Serial N o. 212,37 3

(Cl. G-82) 12 Claims. 1

This invention relates to circuit interrupters and more particularly to compressed air operated circuit interrupters.

An object of the invention is to provide a pneumatically operated circuit interrupter which may be tripped open free of the operating means.

Another object of the invention is to provide a circuit interruptor of the compressed gas operated type that may readily be assembled for tripfree or non-trip-free operation.

Another object of the invention is to provide a circuit interrupter embodying a. novel trip-free operating mechanism which can readily be changed to a non-trip-free mechanism or Vice versa.

Another object of the invention is to provide a circuit interrupter embodying a novel operating mechanism which is capable of assembly as a trip-free or a non-trip-free mechanism by adding or omitting a minimum of parts.

Another object of the invention is to provide a circuit interrupter of the compressed gas operated type that is trip free of the operating mechanism which can be made non-trip-free of the operating mechanism by the elimination of one of the elements.

The novel features that are considered characteristic of the invention are set forth in the appended claims. The invention itself, however, both as to structure and operation, together with additional objects and advantages thereof will be best understood from the following detailed description thereof when read in connection with the accompanying drawings.

In said drawings:

Figure 1 is an elevational view partly in section of a circuit breaker operating mechanism embodying the principles of the invention.

Fig. 2 is a top plan view of the operating mechamsm.

Fig. 3 is a detail plan View of a part of the latching mechanism.

Fig. 4 is a fragmentary elevational view partly in section showing the operating mechanism arranged for non-trip-free operation.

Referring to Fig. 1 of the drawings, the circuit interrupter, shown schematically at 'l may be of any 'conventional construction either of the oil break or air break type. The circuit breaker as schematically shown, comprises stationary contact means S and movable contact means l I. Although illustrated as a single pole circuit interrupter, it will be understood that the interrupter may have a set of contacts 9 and H for each pole thereof with the movable contacts mechanically connected for simultaneous operation in the usual manner.

The circuit interrupter is biased to open circuit position by means of an accelerating spring i5, and the interrupter is mechanically connected to the operating mechanism indicated generally at El by a suitable connecting means comprising a lever I9 pivoted at 2l on a fixed support. One end of the lever i9 is pivotally connected to a breaker lift rod 23 and the other end is pivotally connected to an operating rod 25 which is, in turn, connected to the operating mechanism Il.

The operating mechanism comprises a main casting El which is formed to provide a cylinder 29 closed at the upper end by an integral part of the casting. A closure member 3| suitably secured to the lower end of the cylinder 29 is provided with a relatively large port 33 open to the atmosphere.

Disposed in the cylinder 29 is an operating piston 35 secured by means of a nut 3l to a piston rod 39. The piston rod 39 extends through a substantially air tight opening in the upper end of the casting El and is pivotally connected by means oi a pin @l to a pair of outer levers 43 (Figs. 1 and 2). At their left hand ends the levers 43 are pivotally supported on the upper end of links li5 by means of a pin 4l, the lower end of the link l5 being pivotally supported by means of a pin t9 pivoted in a pair of spaced ears 5i (only one being shown) formed integral with the casting 2l. Also pivotally supported on the pin Il? is a pair of inner levers 53 which are pivotally connected by means of a pin 55 to the lower end of the breaker pull rod 25.

The right hand ends of the outer levers 43 are rigidly connected by means of a cross bar 5l suitably secured thereto, for instance, by welding. The levers t3 between them carry a pin 59 upon which is mounted a latch roller 6l normally engaged by a main latch 63 to maintain the outer levers 43 in the closed position. Also mounted on the pin 59 is a latch 65 which normally engages a latch roller El mounted on a pin 69 supported between the inner levers 53 to maintain the inner levers 53 and the interrupter in closed position. The latch comprises a pair of spaced latch members disposed one on each side of the main latch 63 and rigidly connected by means of a pin 'iL The latch 55 is biased to latching position by means of a compression spring 13.

The main latch 63 is pivotally mounted on the casting 21 by means of a pin l5 and is biased to latching position by a compression spring ll. The main latch 63 is of the slip-off type, that is, its

-rod Si.

ergization of the coil 55 which may be eiected latching configuration is such that it will not, of itself, restrain the mechanism against the opening force of the accelerating spring l5. A sec-V ondary latch 'i9 is provided to hold the main latch in latching position. The secondary latch 'I9 is pivoted on the casting by means of a pivot pin Si and is biasedwinto latching engagement with the-main latch 53 by a spring 83. The latch 'l5 has a tail piece 55, the free end oi which is disposed above a trip rod 8l forming part of a tripping electromagnet indicated Agenerally at S5. Also pivoted on the pin 8l is an arm 5| having its free end disposed above the trip rod to be engaged and actuated thereby. .The arm 9i isprovided with a projection 93 disposed beneath a tail 55 on the latch member 55 so' that when' the .secured to theside of the casting 2l.

arm Si is actuated the projection i!4 engages the tail 95 and actuates the latch 55 to unlatching position.

The trip magnet 89 comprises a magnet yoke 91, anenergizing coil 59 anda movable armature lll! attached to the lower end of the trip The interrupter is tripped open by enin any suitable manner, for instance, by the well known fault relay. Energization of the tripmagnet 39 causes the armature lill to move the trip rod 8? upwardly to actuate the arm 9i and the auxiliary latch '59. Actuation of the arm 9! causes the projection 95 to engage the tail 95 and vactuate the latch 55 to unlatching position. This disconnects the inner levers 53 (Figs. 1 and 2) from the outer levers i3 and permits the accelerating spring i5 to move the movable contact means H and the breaker mechanism including the inner levers 53 toward the open position free of theouter levers 43 and the operating piston 35. At approximately the same time the auxiliary latch 19 is actuated to unlatching position by the trip rod 8l engaging the tail S5 thereof Whereupon the force of a strong spring 03 (Fig. 1) compressed between the cylinder closure 3l and the piston 35 moves the pistonvand the piston rod- 39 upwardly'rotating the outer levers 43 counterclockwise. This action forces the main latch 53 to unlatching position permitting continued counterclockwise or retrieving movement of the outer levers d3. Since the latch 65 is pivoted on the pin 55 which is carried by the outer levers 45 the latch 55l moves therewith and during the opening movement of the breaker over takes the inner levers and is reengaged with the latch roller 5l thereon to reconnect the inner and outer levers to thereby reconnect the breaker mechanism to the operating piston 35 at least by the time the breaker `reaches full open position.

After the Vlatch roller 5l (Fig. 1) is free of the latch F53,v the spring ll restores the .latch to latching position. In order to prevent breakage of the parts when the breaker is operated to the-closed position, it is necessary to prevent the auxiliary latch 'I9 from. reengaging the latch 53 untilthe-breaker is ully closed. This is accomplished by means cfa holding lever |55 pivotally mounted on the pin 3l. The holding lever W5 .is provided with a projection lill extending laterally beneath the tail 85 oi the auxiliary latch l5. and also nasa projection it adapted to be engaged by the lever (i3 in the closed position of the breaker to hold the holding lever in the position shown. .The holding lever 05 is biased to holdingposition by means of a spring iii that is somewhat strongerthan the spring 53 which biases the auxiliary latch 79 to latching position .present invention.

so that when the lever 43 moves counterclockwise the spring il! moves the holding lever 05 to engage the projection E01 thereon with the tail S5 of the auxiliary latch l5 and hold the latch in unlatching position.

The circuit interrupter is adapted to be closed by compressed'gas admitted tothe cylinder 29 above the piston 35. Compressed gas is admitted to the cylinder 25 from an auxiliary tank H3 (Fig. l) through an inlet passage H5 controlled by amain inlet valve indicated generally at lll Operation of the inlet valve Iii is controlled by an electromagnetically operated pilot valve i I9.

The mainzinletvalve lil and the pilot valve Eil'are fully `disclosed in Patent 2,408,199, issued .September 24,1945 to J. M. Cumming and R. C.

Cunningham and assigned to the assignee of the For this reason, a detailed disclosure of these elements is not included herein,since, for a complete understanding thereof,

"referencemay be had to the above noted patent.

The pilot valve HS is operated by an electromagnet l2! which, when energized, causes opening of the pilot valve i I9 to admit compressed gas from the tank l I3 to operate the main inlet valve l il. Operation of theinlet valve i il admits compressed gas to the upper end of the cylinder 25 which drives the'piston 35 quickly downward to close to the interrupter.

When the mechanism is operated to the closed position, the operating lever i3 moves in a clockwise direction, and near the end of its closing movement, the latch roller 5i engages the inclined surface of the main latch 63. As the latch roller El passes along the inclined surface, the latch 63 is rotated counterclockwise until the roller passes the nose of the latch whereupon the spring 1l' restores the main latch 53 to latching position. As the roller 6i passes the nose of the latch 53, the lever 53 engages the projection lilg on the holding lever |55 and rotates the holding lever to its normal position permitting the spring 83 to restore the auxiliary latch 'l5 to latching position.

The arm 5i is biased to normal position by gravity or by spring means (not shown) and returns'to normal position as soon as the tripping magnet is deenergized. A cutaway portion is provided on the under side of the arm 9| to prevent interference of the projection |57 of the holding lever |55 therewith.

Should the breaker be closed against a fault on the line the tripping magnet 823 would be immediately energized to trip the breaker free of the closing means. The breaker would go immediately to the open position but the high-pressure air in the cylinder 29 Would prevent quick recoupling of the closing mechanism to Vthe breaker. ln order to facilitate high-speed recoupling of the colsing mechanism to thebreaker and reclosing of the breaker there is provided an exhaust-valve mechanism 23 (Fig. 2) which controls a relatively large exhaust port |25 (Fig. 1). The exhaust valve mechanism is fully disclosed in Patent No. 2,403,082, issued July 2, 1946 to A. W. I-lill and J. M. Cumming, and assigned to the assignee of the present invent-ion. A detailed disclosure of the exhaust valve mechanism Vis not included herein since reference may be had to the above noted Patent 2,403,082 for a complete understanding thereof.

The exhaust valve device E23 (Fig. 2) is operated to open the exhaust ports (Fig. 1) by the high-pressure air inthe cylinder 29 under the control of a valve indicated at I 2l. 'Ihe valve |21 controls a passage |29 communicating the cylinder 29 with a tube |3| (Fig. 2) which, in turn, communicates with the exhaust valve device |23. When the breaker closes in against a fault the tripping magnet 89 is energized and trips the breaker free of the closing mechanism in the previously described manner, and, at the same time, opens the valve |27 admitting highpressure closing air from the cylinder through the passage |29 and tube |3| to effect opening of the exhaust valve device |23 which quickly dumps the high-pressure air from the cylinder. This permits the spring H23 (Fig. 1) to eiect high-speed recoupling of the piston 35 to the breaker mechanism at least by the time the breaker reaches full open position. The circuit breaker is then closed in the previously described manner.

An important feature of the invention is that the interrupter may be assembled as a trip-free or non-trip-free interrupter by the inclusion or omission of one of the elements. Also the interrupter may readily be altered in the neld from a trip-free to a non-trip-free mechanism or vice versa in the same manner.

All that is necessary to change the interruptor mechanism from trip-free to non-trip-free operation is to remove the latch 65 (Fig. l) which releasably restrains the inner levers 53 in the closed position, and to replace the pin 69 upon which the latch roller El is mounted with a longer pin |33 (Fig. 4) which extends through both the inner levers 53 and the outer levers 43 thus coupling the breaker operating rod 25 directly to the piston rod 39. The mechanism is shown in Fig. 4 in this con-dition, that is, arranged for non-tripfree operation. It will be noted that the member 9| (Fig. l) has also been eliminated from the Fig. 4 arrangement, however, this is merely a matter of convenience of assembly and, should the change from trip-free to non-trip-free operation be made in the 'held the element 9! may be left in place since, with the removal of the latch 65, the element 9i is without eilect.

Having describe-d the invention in accordance with the patent statutes, it is to be understood that various changes and modinoations may be made in the structural details and combinations of elements disclosed without departing from some of the essential features of the invention.

I claim as my invention:

1. A circuit interrupter having a power operated closing means, a rst lever connected to said interrupter, a second lever connected to said closing means, a common pivot for said levers, a first latch mounted on a nxed pivot for releasably restraining said first lever, a holding latch nor-- mally holding said rst latch in'latching position, a second latch mounted on said rst lever for releasably restraining said second lever, and a single trip device operable to simultaneously engage and positively actuate said holding latch and said second latch to permit high-speed opening movement of said interrupter free of said closing means and to permit high-speed movement of said closing means to recouple said closing means to said interruptor.

2. A circuit interrupter comprising stationary and movable contact means, spring means biasing said movable contact means in opening direction, compressed gas operated means comprising a cylinder and a piston movable therein for actuating said movable contact means to closed position, a rst lever connected to said piston, a second lever connected to said movable contact means, a iirst main latch mounted on a xed pivot for releasably restraining said rst lever in closed position, an auxiliary latch releasably restraining said first main latch in latching position, a second main latch carried by said :first lever releasably restraining said second lever and said movable contact means in closed position, and electromagnetic trip means operable to simultaneously actuate said auxiliary latch and said second main latch to effect opening movement of said movable contact means free of said piston.

3. A circuit interruptor comprising stationary and movable contact means, spring means biasing said movable contact means to open position, power means for actuating said movable contact means to closed position, a first lever connected to said power means, a second lever connected to said movable contact means, a common pivot for said levers, a rst main latch mounted on a hired pivot normally releasably restraining said rst lever in closed position, an auxiliary latch mounted on a fixed pivot normally restraining said iirst latch in latching position, a second main latch pivotally mounted on said rst lever normally releasably restraining said second lever and said movable contact means in closed position, and a trip device operable to simultaneously engage and positively actuate said auxiliary latch and said second main latch to eiect opening movement of said movable contact means.

4. A circuit interruptor having power operated closing means, spring means for opening said interrupter, a pair of levers, one of said levers being connected to said interruptor and the other of said levers being connected to said closing means, latch means releasably restraining said other lever in operative position, said latch means being operable to permit opening movement of said one lever and said interruptor by said spring with associated movement ci said other lever and said closing means, selectively insertable latch means operable to permit opening movement of said one lever and said interrupter by said spring without associated movement of said other lever and said closing means, and a trip device operable to effeet unlatching operation of said latch means.

5. A circuit interrupter having power operated closing means, spring means for opening said interrupter, a pair of levers, one of said levers being connected to said interrupter and the other of said levers being connected to said closing means, pivot means pivotally supporting said levers at one end thereof, said levers having aligned openings therein adjacent the other end thereof for receiving a pin whereby said levers may be held in xed relation to each other, latch means releasably restraining said levers in operative position, and a trip device for actuating said latch means to effect opening of said interrupter.

6. A circuit interrupter having stationary and movable contacts, spring means biasing said interrupter to open position, power operated means for closing said interrupter, a pair of levers, one of said levers being connected to said interrupter and the other lever being connected to said power operated means, pivot means pivotally supporting said levers at one end thereof, means including a pin and a latch for selectively connecting the other end of one lever for unitary movement with the other lever and to provide a releasable connection between said levers, and a trip device oparable to release-said levers and eiect-opening of said. interrupter.

i 7,. A circuit interrupter having stationary and movable contacts, spring means biasing said interrupter to open position, power operated means `for closing said interrupter, a pair of levers, one

of said levers being connected to said interrupter and the other lever being connected to said power 'operated means, pivot means pivotally supporting .said levers at one end thereof, a releasable redevice operable to release said restraining device and eiect opening of said interrupter.

8. A circuit interruptor having stationary and movable contacts,ispring means biasing said interrupter to open position, power operated means for closing said interrupter, a pair of levers, one ofy said levers being connected to said interrupter Vand the other lever being connected to said power operated means, pivot means pivotally supporting-said levers at one end thereof, a releasable restraining device for holding said lever connected to said power operated means, a latch removably mounted on one of said levers and releasably engaging a part on the other of said levers, a portion on each of said levers through which said two levers may be held in fixed relation to each other, and a trip device operable to release both said restraining device and said latch and-elect'opening of said interrupter.

9. A circuit interrupter having stationary land movable contacts, spring means biasing said interruptor to open position, power operated means for closing said interrupter, a pair of levers, one of said levers being connected to said interrupter and the other lever being connected to said power operated means, pivot means pivotally supporting said Vlevers at one end thereof, a releasable restraining device for holding said lever connected to said power operated means, a latch mounted on one of said levers and releasably engaging a part on the other of said levers, aligned openings in each of said levers through which said two levers may be held in xed relation to each other, and a trip device operable to release both said restraining device and said latch and eiect opening of said interrupter.

10. A circuit interruptor having stationary and movable contacts, spring means biasing said interruptor to open position, power operated means for closing said interrupter, a pair of levers, one of said levers being connected to said interruptor and the other lever being connected to said power operated means-pivot means pivotallysupporting said levers at one end thereof, a reieasable Arestraining deviceY for holding said lever connected to said power'operated means, a removable element connecting said two levers for movement in unison both when said restraining device is released and when said power operated means is operated, and a trip device operable to release said restraining device and eiect opening of said,V

interrupter by movement of both of .said levers in unison.

1l. In a circuit interruptor having power operated closing means, spring means biasing said interrupter to open position, a pair of pivoted levers, one or" said levers being connected to said interrupter and-the other lever being connected to 'said power operated closing means, restraining means releasably. restraining said other lever in operative position, a latch removably mounted on said other leverand releasably engaging said one lever, said latch being operable to permit opening movement of said one lever free of said'other 'lever and said power operated closing means, a

pin removably mounted insaid levers for connecting said levers for unitary .movement, said latch and said pin being selectively mounted on said levers, and a trip device operable to release said levers and eiect opening of said interrupter.

12. A circuit interrupter having spring means for opening said interrupter to open position, closing means for closing said interruptena iirst pivoted element connected to said interrupter, a second pivoted element connected to said closing means, restraining means releasably restraining said second element in operative position, a latch removably mounted on one of said elements `and releasably engaging a part of the other of said elements, said latch being operable to release said first element and effect opening movement of said rst element free of said second element and said closing means, a member removably mounted on said elements for connecting said elements for movement of bothof said elements, said interrupter and said closing means in unison, said latch and said member being selectively mounted on said elements, and a trip device operable to release said restraining means and eiect opening of said interrupter.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,190,060 Woli July 4, 1916 1,241,533 MacNeill Oct. 2, 1917 1,647,632 Jacobs Nov. l, 1927 2,361,178 Cumming Oct. 24, 1944 

